Do most mass shootings happen in gun-free zones?

A Jan. 6 mass shooting at the Fort Lauderdale-Hollywood International Airport left five people dead and stranded thousands of passengers. (Miami Herald.)

In the wake of mass shootings at the Pulse night club in Orlando and at the Fort Lauderdale airport, Florida lawmakers are expected to act on a series of bills to expand where people can carry their guns.

The bills would allow concealed-carry permit holders to carry their guns in places such as airports, schools, college campuses, police stations and polling places. Florida leads the nation in conceal-carry permits with more than 1.7 million permits.

Republican House Speaker Richard Corcoran supports expanding the list of where permit holders can carry their guns, possibly as a way to avert future attacks. (So does President Donald Trump, who promised to get rid of gun-free zones in schools and military bases.)

"Most of these mass shootings take place in arenas where you're not allowed to have a concealed weapons permit," he told CBS4 Miami’s Jim DeFede on Feb. 12. (By "arenas" Corcoran seemed to be referring to places in general, not sports arenas.)

Corcoran argued that people who commit mass shootings say they chose certain areas because they "knew nobody had guns." That raises an interesting question, but it’s separate from the focus of this fact-check: whether most mass shootings happen in places where concealed carry permits don’t apply, or "gun-free zones."

Corcoran was citing research from a pro-gun advocate who reached that conclusion. But anti-gun advocates have argued that the data isn’t so clear cut; they see other patterns in the statistical evidence. Overall, the evidence remains murky and depends on how researchers define "gun-free" or "mass shooting."

Varying definitions of mass shootings

Corcoran’s spokesman said he was referring to the numbers of mass public shootings compiled by economist John Lott, president of the pro-gun Crime Prevention Research Center.

Lott’s research has been quoted by those who support expanding gun rights, but academics often attack his research as flawed. His book More Guns, Less Crime has been a subject of ongoing academic and policy debates as well numerousfact-checks.

His book argues that crime data over multiple years shows reductions in crime in states that have "right to carry" laws. But many other academics have said his work doesn’t account for other factors that influence crime rates, and that he manipulates the data to reach his conclusions. The National Academies of Sciences concluded in 2005 that "no link between right-to-carry laws and changes in crime is apparent in the raw data."

Before we delve into the numbers compiled by Lott, we will explain why it’s complicated to make sweeping claims of mass shootings in gun-free zones.

FBI spokesman Stephen Fischer pointed to a 2012 law setting the threshold for a "mass killing" as three or more people killed, but another report by the federal Congressional Research Service says that "mass murder" has been defined generally as a threshold of four or more deaths. Lott points to the types of shootings the FBI included in this study of active shooter situations, but that study clearly says it isn’t covering all mass shootings.

Lott said he included mass shootings in which four or more were killed that occurred in public, and he excluded those that occurred within the commission of another crime such as an armed robbery.

Lott’s data showed that between 1988 and 2015, about 3.8 percent of mass shootings occurred in areas where guns were allowed.

Everytown for Gun Safety found that among 133 mass shootings between January 2009 and July 2015, 70 percent took place in private homes while 13 percent took place in "gun-free zones," where carrying of concealed guns were prohibited. Another 17 percent took place in public areas where the carrying of firearms are allowed.

In Klarevas’ book Rampage Nation, he said that Lott has used too loose a concept of gun-free zones.

Klarevas disagrees with gun advocates who define a "gun-free zone" as simply an area that bans private citizens from carrying a gun.

For example, Lott characterized Fort Hood and Washington Navy Yard, military sites attacked by gunmen, as gun-free despite the presence of armed security.

"There’s an obvious logical problem with such a conceptualization: How can a place be a gun-free zone if guns are present?" Klarevas writes. "The implication is that rampage shooters are only deterred by armed civilians, not by armed guards and cops. But that’s an absurd suggestion."

Klarevas uses three definitions: he refers to "gun-free zones" as places where civilians are not allowed to carry guns, and there aren’t armed personnel stationed on the property. He calls "gun-restricting zones" as places where civilians can’t carry guns, yet armed security is routinely present -- such as military facilities or certain college campuses. He refers to places that allow civilians to carry guns as "gun-allowing zones."

Using these categories, Klarevas examined 111 shootings since 1966 in which six or more people had been killed in each incident -- regardless of whether it occurred in a public or private location or if it was in the commission of another crime.

He found 13 took place in gun-free zones and five took place in gun-restricting zones. That means that the majority occurred in areas where there was no evidence that private guns were prohibited.

Since Klarevas includes mass shootings in private residences or during the commission of another crime, that means that he counts several additional incidents that aren’t factored in by Lott.

For example, as a mass shooting in a "gun-allowing zone," Klarevas counts a gunfight between two rival biker gangs in Waco,Texas, in 2015 that left nine people dead. So that’s an example of a shooting that wasn’t in a gun-free zone that is omitted from Lott’s calculations.

The two also disagree on how to characterize whether guns were allowed at certain locations. Lott says that the shooting at Umpqua Community College in Oregon was in a gun-free zone and points to a school policy that bans possession of firearms "except as expressly authorized by law or college regulations."

Umpqua Community College spokeswoman Anne Marie Levis previously told PolitiFact Florida the school’s gun-free policy didn’t apply to students with a valid permit. "UCC was never designated as a ‘gun-free zone’ by any signage or policy," she said. "Umpqua Community College does comply with state law by allowing students with concealed carry licenses to bring firearms on campus."

Our ruling

Corcoran said, "Most of these mass shootings take place in arenas where you're not allowed to have a concealed weapons permit."

Corcoran cites research by an advocate for gun rights who used a strict definition to define places where guns were not allowed. In reality, there are places where concealed weapons are permitted, places where police or security officers openly carry weapons, and places where concealed weapons are not permitted. Additionally, there are different ways to define mass shootings.

We found that advocates for more gun control analyzed the data and reached different conclusions.

Our assessment is that it is difficult to draw broad conclusions about the motivations of the perpetrators of mass shootings or whether they are influenced by gun restrictions. We rate Corcoran’s statement Half True.

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